Some statisticians investigated the accuracy of using ultrasound to test for a genetic marker of a medical condition. let d denote that the fetus has the genetic marker and n denote that the ultrasound test is normal. then, the statisticians desire the probability p(d|n). use bayes's rule and the following probabilities to find the desired probability.

It is e) i am not sure if you have any questions or need any

Look, when you want to do something like put it like x^2. x2 could mean x² or x₂. so to clear confusion, know the notation. to find the product multiply the x's and you get -8x and the y's and you get 6y. since it's all being multiplied it is just -8x6y, or answer a. although the better answer is -48xy(combining -8 and 6) because you should multiply constants whenever you can.